Granted Patent B1

US 7,695,761 · App. 11/643,446 · Granted Apr 13, 2010

Abstract

Claims (30)

1. A method for providing a spin tunneling element comprising:

providing a pinned layer;

providing a barrier layer having a first crystal structure, and having a texture; and

providing a free layer having a first ferromagnetic layer and a second ferromagnetic layer, the first ferromagnetic layer being adjacent to the second ferromagnetic layer and between the second ferromagnetic layer and the barrier layer, the first ferromagnetic layer having the first crystal structure and the texture, the second ferromagnetic layer having a second crystal structure different from the first crystal structure after fabrication of the spin tunneling junction is complete, the step of providing the free layer further including:

depositing the first ferromagnetic layer having the first crystal structure and the texture;

performing a rapid thermal anneal on the first ferromagnetic layer such that the first ferromagnetic layer retains the first crystal structure and the texture;

depositing the second ferromagnetic layer having the second crystal structure after the rapid thermal anneal has been performed.

2. The method of claim 1 wherein the rapid thermal anneal performing and the second ferromagnetic layer depositing steps are provided without exposing the spin tunneling element to an external environment.

3. The method of claim 1 wherein the free layer providing further includes:

performing an additional anneal at a temperature of not more than three hundred sixty degrees Centigrade in a magnetic field of at least five thousand and not more than fifteen thousand Gauss.

4. The method of claim 1 wherein the barrier layer includes MgO.

5. The method of claim 4 wherein the barrier layer includes MgOX, where X is a nonmagnetic material.

6. The method of claim 4 wherein the texture is [100].

7. The method of claim 4 wherein the first ferromagnetic layer includes CoFe.

8. The method of claim 7 wherein the second ferromagnetic layer includes NiFe.

9. The method of claim 1 wherein the first crystal structure is BCC.

10. The method of claim 9 wherein the second crystal structure is FCC.

11. The method of claim 1 wherein the free layer providing further includes:

depositing the first ferromagnetic layer in a deposition chamber;

moving the spin tunneling element from the deposition chamber to a rapid thermal anneal chamber without exposing the spin tunneling element to an external environment;

performing the rapid thermal anneal on the first ferromagnetic layer in the rapid thermal anneal chamber;

moving the spin tunneling element from the rapid thermal anneal chamber to the deposition chamber without exposing the spin tunneling element to the external environment; and

depositing the second ferromagnetic layer after the rapid thermal anneal has been performed.

12. A method for providing a spin tunneling element comprising:

providing a barrier layer, the barrier layer being insulating and including MgO, having a first crystal structure, and having a texture; and

depositing a first ferromagnetic layer in a first deposition chamber, the first ferromagnetic layer including CoFe having the first crystal structure and the texture;

using at least one transfer station to move the spin tunneling element from the deposition chamber to a rapid thermal anneal chamber without exposing the spin tunneling element to an external environment;

performing a rapid thermal anneal on the first ferromagnetic layer in the rapid thermal anneal chamber without changing the crystal structure and texture of the first ferromagnetic layer;

using the at least one transfer station to move the spin tunneling element from the rapid thermal anneal chamber to a second deposition chamber without exposing the spin tunneling element to the external environment; and

depositing a second ferromagnetic layer in the second deposition chamber after the rapid thermal anneal has been performed, the second ferromagnetic layer include including NiFe.

Assignments (7)